Telephone-mouthpiece.



0. THOKLE.

TELEPHONE MOUTHPIECE.

APPLICATION FILED AUG. 16. 1916.

Patented Feb. 11, 1919.

UNITED STATES PATENT OFFICE.

OLAUS THOKLE, OF MAN DAL, NORWAY.

TELEPHONE-MOUTHPIECE.

Application filed August 16, 1916.

To all whom it may concern:

Be it known that I, OLAUS THoxLE, a subject of the King of Norway, residing at Mandal, Norway, have invented certain new and useful Improvements in Telephone- Mouthpieces; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

My invention relates to means for obtaining a better and clearer transmission of the sound through telephone mouth pieces, and the like.

It is well known that the form of the mouth-piece through which the sound is transmitted from the mouth' of the speaker to the telephone diaphragm greatly influences the clearness of speech.

I have now found that the sound transmission is greatly improved when I provide the interior of the mouth piece with one or more partitions in such a Way that the sound is transmitted from the outer part of the mouth piece to its inner opening communicating with the diaphragm chamber through a plurality of separate channels.

In the accompanying drawing is illustrated the executional form which I have through experimenting found to give the best results.

According to this a somewhat elongated shell forming the telephone mouthpiece is at a suitable distance from its outer edge provided with two partitions A and B arranged crosswise so as to form four separate channels of sectorshaped cross-section. It has been found suitable to let the partitions end at some distance from the outer edge of Camel of this patent may be obtained for Specification of Letters Patent.

Patented Feb. 11, 1919.

Serial No. 115,198.

the mouth piece, thereby leaving an undivided chamber in the outer part of the mouth piece where the sound waves enter. 7

The effect of the separate channels seems to be that the pressure existing at the entrance of the mouth piece may be transmitted through the separate channels without being exposed to the disturbing influence of the curved mouth-piece walls on the sound waves through reflection. In commontelephone mouth pieces the sound waves willespecially in loud speakingbe very much disturbed-thrown in a whirl so to say-by the reflection, thereby effecting a bad sound transmission to the diaphragm. The subdivision in channels tends to ameliorate the reflection effects.

The mouth-piece shown is particularly adapted for use on what are known as combined telephones, used by operators, where a transmitter and a receiver are mounted on a handle and arranged at right angles to each other.

The invention may also be applied to talking machine trumpets.

Claim:

A telephone mouth-piece comprising an elongated tapering shell having crossed partitions therein extending across the shell and forming separate sector-shaped sound channels extending from the inner end of the shell to near the outer end of the latter, said partitions being extremely thin, whereby the total cross-area of the shell is not materially decreased.

In testimony that I claim the foregoing as my invention, I have igned my name in presence of two subscribing witnesses.

OLAUS THOKLE.

Witnesses OLAUS ALVESEN,

H. NEURER.

five cents each, by addressing the Commissioner of Patents,

Washington, .D. 0." 

